This application claims priority to prior application JP 2002-208998, the disclosure of which is incorporated herein by reference.
This invention relates to a solid electrolytic capacitor and a method of fabricating it and, in particular, to technique of sealing and wrapping of the solid electrolytic capacitor using a flat-shaped capacitor element.
Surface mounted type solid electrolytic capacitors are well known in the art. For example, the surface mounted type solid electrolytic capacitor comprises an anode electrode made of valve-action metal such as tantalum, aluminum or the like, a dielectric obtained by oxidizing the valve-action metal serving as a base material of the anode electrode, a conductive layer made of manganese dioxide, a conductive macromolecule or the like firmly formed on the dielectric, and a cathode electrode obtained by laminating a graphite layer or a silver pasted layer on the conductive layer. In such surface mounted type solid electrolytic capacitors, ones each comprising a capacitor element having a configuration of pillar body such as a column or a square pole are well known in the art. As the others, capacitors each using a flat shaped element are disclosed, for example, in Japanese Unexamined Patent Publication Tokkai No. Hei 5-275,290 or JP-A 5-275290. This invention relates to a surface mounted type solid electrolytic capacitor using such flat capacitor element.
Speaking characteristics of conventional surface mounted type solid electrolytic capacitors described above from the point of view of relevance of this invention, any capacitor is covered with an exterior finishing resin body formed by molding the surrounding whole of an element by thermosetting resin.
With this structure, it is difficult to thin thickness of the whole of the capacitor including the exterior finishing resin. In addition, sealing of the exterior finishing resin is not always sufficient.
It is therefore an object of the present invention to provide a surface mounted type solid electrolytic capacitor using a flat solid electrolytic capacitor element which is capable of thinning a thickness of the whole of the capacitor.
It is another object of the present invention to provide a surface mounted type solid electrolytic capacitor using a flat solid electrolytic capacitor element which is capable of improving sealing of the capacitor.
Other objects of this invention will become clear as the description proceeds.
On describing the gist of an aspect of this invention, it is possible to be understood that a solid electrolytic capacitor comprises a flat solid electrolytic capacitor element having first and second surfaces opposite to each other and a plate-shaped external cathode terminal disposed on the first surface of the flat solid electrolytic capacitor. According to the aspect of this invention, the above-mentioned solid electrolytic capacitor further comprises a double-sided thermal adhesive film impregnated with thermosetting resin put on the second surface of the flat solid electrolytic capacitor and a reinforcement plate fastened on the double-sided thermal adhesive film impregnated with thermosetting resin. The flat solid electrolytic capacitor is sandwiched between the plate-shaped e external cathode terminal and the double-sided thermal adhesive film impregnated with thermosetting resin, the reinforcement plate. The flat solid electrolytic capacitor has side faces sealed with an eluted material of thermosetting resin impregnated in the double-sided thermal adhesive film impregnated with thermosetting resin.